PLAA suppresses ovarian cancer metastasis via METTL3-mediated m6A modification of TRPC3 mRNA

Targeting JUNB to modulate M2 macrophage polarization in preeclampsia

Preeclampsia (PE) is a complex disorder affecting pregnant women, leading to significant maternal and fetal morbidity and mortality. Understanding the cellular dynamics and molecular mechanisms underlying PE is crucial for developing effective therapeutic strategies. This study utilized single-cell RNA sequencing (scRNA-seq) to delineate the cellular landscape of the placenta in PE, identifying 11 distinct cell subpopulations, with macrophages playing a pivotal role in mediating cell-cell communication. Specifically, the transcription factor JUNB was found to be a key gene in macrophages from PE samples, influencing the interaction between macrophages and both epithelial and endothelial cells. Functional experiments indicated that interference with JUNB expression promoted macrophage polarization towards an M2 phenotype, which facilitated trophoblast invasion, migration, and angiogenesis. Mechanistically, JUNB regulated the MIIP/PI3K/AKT pathway, as evidenced by gene expression analysis following JUNB knockdown. The study further demonstrated that targeting JUNB could activate the PI3K/AKT pathway by transcriptionally activating MIIP, thus promoting M2 polarization and potentially delaying the onset of PE. These findings present new insights into the pathogenesis of PE and suggest a novel therapeutic approach by modulating macrophage polarization.

Ubiquitination and deubiquitination in the regulation of N6-methyladenosine functional molecules

N6 methyladenosine (m6A) is the most prevalent RNA epigenetic modification, regulated by methyltransferases and demethyltransferases and recognized by methylation-related reading proteins to impact mRNA splicing, translocation, stability, and translation efficiency. It significantly affects a variety of activities, including stem cell maintenance and differentiation, tumor formation, immune regulation, and metabolic disorders. Ubiquitination refers to the specific modification of target proteins by ubiquitin molecule in response to a series of enzymes. E3 ligases connect ubiquitin to target proteins and usually lead to protein degradation. On the contrary, deubiquitination induced by deubiquitinating enzymes (DUBs) can separate ubiquitin and regulate the stability of protein. Recent studies have emphasized the potential importance of ubiquitination and deubiquitination in controlling the function of m6A modification. In this review, we discuss the impact of ubiquitination and deubiquitination on m6A functional molecules in diseases, such as metabolism, cellular stress, and tumor growth.

Interactions of Histone Deacetylase 6 with DNA Damage Repair Factors Strengthen its Utility as a Combination Drug Target in High-Grade Serous Ovarian Cancer

High-grade serous ovarian cancer (HGSOC) is the deadliest gynecologic malignancy in women. The low survival rate is largely due to drug resistance. Approximately 80% of patients who initially respond to treatment relapse and become drug-resistant. The lack of effective second-line therapeutics remains a substantial challenge for BRCA-1/2 wild-type HGSOC patients. Histone Deacetylases (HDACs) are promising targets in HGSOC treatment; however, the mechanism and efficacy of HDAC inhibitors are understudied in HGSOC. In order to consider HDACs as a treatment target, an improved understanding of their function within HGSOC is required. This includes elucidating HDAC6-specific protein-protein interactions. In this study, we carried out substrate trapping followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to elucidate HDAC6 catalytic domain (CD)-specific interactors in the context of BRCA-1/2 wild-type HGSOC. Overall, this study identified new HDAC6 substrates that may be unique to HGSOC. The HDAC6-CD1 mutant condition contained the largest number of significant proteins compared to the CD2 mutant and the CD1/2 mutant conditions, suggesting the HDAC6-CD1 domain has catalytic activity that is independent of CD2. Among the identified substrates were proteins involved in DNA damage repair including PARP proteins. These findings further justify the use of HDAC inhibitors as a combination treatment with platinum chemotherapy agents and PARP inhibitors in HGSOC.

Sulforaphene suppressed cell proliferation and promoted apoptosis of COV362 cells in endometrioid ovarian cancer

Aim

N6-methyladenosine (m6A) RNA methylation exerts a regulatory effect on endometrioid ovarian cancer (EOC), but the specific m6A regulator genes in EOC remain to be explored. This study investigated that sulforaphene (Sul) is implicated in EOC development by regulating methyltransferase-like 3 (METTL3).

Methods

The dysregulated m6A RNA methylation genes in EOC were determined by methylated RNA immunoprecipitation (MeRIP-seq) and RNA sequencing. The roles of METTL3 and/or Sul on viability, proliferative ability, cell cycle, and apoptosis of EOC cells were determined by MTT, colony formation, flow cytometry, and TUNEL staining assay, respectively. The expression of METTL3 and apoptosis-related proteins in EOC cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot assays.

Results

Five m6A RNA methylation regulators (METTL3, ELF3, IGF2BP2, FTO, and METTL14) were differentially expressed in EOC, among which METTL3 had the highest expression level. Silencing METTL3 reduced the clonal expansion and viability of EOC cells, and caused the cells to arrest in the G0/G1 phase. This also promoted apoptosis in the EOC cells and activated the FAS/FADD and mitochondrial apoptosis pathways. In contrast, overexpressing METTL3 had the opposite effect. Sul, in a dose-dependent manner, reduced the viability of EOC cells but promoted their apoptosis. Sul also increased the levels of IGF2BP2 and FAS, while decreasing the levels of KRT8 and METTL3. Furthermore, Sul was able to reverse the effects of METTL3 overexpression on EOC cells.

Conclusions

Sul could suppress cell proliferation and promote apoptosis of EOC cells by inhibiting the METTL3 to activate the FAS/FADD and apoptosis-associated pathways.

Calcium signals and potential therapy targets in ovarian cancer (Review)

Ovarian cancer (OC) is a deadly disease. The poor prognosis and high lethality of OC are attributed to its high degrees of aggressiveness, resistance to chemotherapy and recurrence rates. Calcium ion (Ca2+) signaling has received attention in recent years, as it appears to form an essential part of various aspects of cancer pathophysiology and is a potential therapeutic target for OC treatment. Disruption of normal Ca2+ signaling pathways can induce changes in cell cycle progression, apoptosis, proliferation and migration and invasion, leading to the development of the malignant phenotype of tumors. In the present review, the main roles of ion channel/receptor/pump‑triggered Ca2+ signaling pathways located at the plasma membrane and organelle Ca2+ transport in OC are summarized. In addition, the potential of Ca2+ signaling as a novel target for the development of effective treatment strategies for OC was discussed. Furthering the understanding into the role of Ca2+ signaling in OC is expected to facilitated the identification of novel therapeutic targets and improved clinical outcomes for patients.

N6-methyladenosine methyltransferase KIAA1429 promoted ovarian cancer aerobic glycolysis and progression through enhancing ENO1 expression

BACKGROUND

Despite improvements in prognosis due to advances in treatment, including surgery, genetic screening, and molecular targeted therapy, the outcomes of ovarian cancer (OC) remain unsatisfactory. Internal mRNA modifications are extremely common in eukaryotes; N6-methyladenosine (m6A) alteration has significant effects on mRNA stability and translation, and it is involved in the pathophysiology of numerous diseases related to cancer.

METHODS

Bioinformatics analysis, quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of vir-like m6A methyltransferase associated (KIAA1429) in OC tissues and cell lines. Several different cell models and animal models were established to determine the role of KIAA1429 in glucose metabolism reprogramming and the underlying molecular mechanism of OC. The mechanism of oncology functional assays, co-immunoprecipitation and a luciferase reporter gene was employed to ascertain how KIAA1429 interacts with important molecular targets.

RESULTS

We reported that KIAA1429 was overexpressed in OC and predicted a poor prognosis. Functionally, KIAA1429 promoted cell growth by inducing proliferation and inhibiting necrosis. Mechanistically, KIAA1429 promoted tumor progression and glycolysis via stabilizing ENO1 mRNA in a way dependent on m6A. Furthermore, we investigated that the SPI1 transcription factor is the main transcription factor that regulates KIAA1429 transcription in OC.

CONCLUSION

Our findings revealed that SPI1/KIAA1429/ENO1 signaling is a novel molecular axis and raises awareness of the vital functions of the changes in KIAA1429 and m6A changes in the metabolic reprogramming of OC. These results identified new potential biomarkers and treatment targets for OC.

RNA epigenetic modifications in ovarian cancer: The changes, chances, and challenges

Ovarian cancer (OC) is the most common female cancer worldwide. Patients with OC have high mortality because of its complex and poorly understood pathogenesis. RNA epigenetic modifications, such as m6 A, m1 A, and m5 C, are closely associated with the occurrence and development of OC. RNA modifications can affect the stability of mRNA transcripts, nuclear export of RNAs, translation efficiency, and decoding accuracy. However, there are few overviews that summarize the link between m6 A RNA modification and OC. Here, we discuss the molecular and cellular functions of different RNA modifications and how their regulation contributes to the pathogenesis of OC. By improving our understanding of the role of RNA modifications in the etiology of OC, we provide new perspectives for their use in OC diagnosis and treatment. This article is categorized under: RNA Processing > RNA Editing and Modification RNA in Disease and Development > RNA in Disease.

Methyltransferase-like proteins in cancer biology and potential therapeutic targeting

RNA modification has recently become a significant process of gene regulation, and the methyltransferase-like (METTL) family of proteins plays a critical role in RNA modification, methylating various types of RNAs, including mRNA, tRNA, microRNA, rRNA, and mitochondrial RNAs. METTL proteins consist of a unique seven-beta-strand domain, which binds to the methyl donor SAM to catalyze methyl transfer. The most typical family member METTL3/METTL14 forms a methyltransferase complex involved in N6-methyladenosine (m6A) modification of RNA, regulating tumor proliferation, metastasis and invasion, immunotherapy resistance, and metabolic reprogramming of tumor cells. METTL1, METTL4, METTL5, and METTL16 have also been recently identified to have some regulatory ability in tumorigenesis, and the rest of the METTL family members rely on their methyltransferase activity for methylation of different nucleotides, proteins, and small molecules, which regulate translation and affect processes such as cell differentiation and development. Herein, we summarize the literature on METTLs in the last three years to elucidate their roles in human cancers and provide a theoretical basis for their future use as potential therapeutic targets.

The emerging role of N6-methyladenine RNA methylation in metal ion metabolism and metal-induced carcinogenesis

N⁶-methyladenine (m⁶A) is the most common and abundant internal modification in eukaryotic mRNAs, which can regulate gene expression and perform important biological tasks. Metal ions participate in nucleotide biosynthesis and repair, signal transduction, energy generation, immune defense, and other important metabolic processes. However, long-term environmental and occupational exposure to metals through food, air, soil, water, and industry can result in toxicity, serious health problems, and cancer. Recent evidence indicates dynamic and reversible m⁶A modification modulates various metal ion metabolism, such as iron absorption, calcium uptake and transport. In turn, environmental heavy metal can alter m⁶A modification by directly affecting catalytic activity and expression level of methyltransferases and demethylases, or through reactive oxygen species, eventually disrupting normal biological function and leading to diseases. Therefore, m⁶A RNA methylation may play a bridging role in heavy metal pollution-induced carcinogenesis. This review discusses interaction among heavy metal, m⁶A, and metal ions metabolism, and their regulatory mechanism, focuses on the role of m⁶A methylation and heavy metal pollution in cancer. Finally, the role of nutritional therapy that targeting m⁶A methylation to prevent metal ion metabolism disorder-induced cancer is summarized.

Phospholipase A2-activating protein induces mitophagy trough anti-apoptotic MCL1-mediated NLRX1 oligomerization

Mitochondrial protein homeostasis is fine-tuned by diverse physiological processes such as mitochondria-associated degradation (MAD), which is regulated by valosin-containing protein (VCP) and its cofactors. As a cofactor of VCP, the mutation of phospholipase A-2-activating protein (PLAA) is the genetic cause of PLAA-associated neurodevelopmental disorder (PLAAND). However, the physiological and pathological roles of PLAA in mitochondria remain unclear. Here, we demonstrate that PLAA partially associates with mitochondria. Deficiency in PLAA increases mitochondrial reactive oxygen species (ROS) production, reduces mitochondrial membrane potential, inhibits mitochondrial respiratory activity and causes excessive mitophagy. Mechanically, PLAA interacts with myeloid cell leukemia-1 (MCL1) and facilitates its retro-translocation and proteasome-dependent degradation. The upregulation of MCL1 promotes the oligomerization of NLR family member X1 (NLRX1) and activation of mitophagy. Whereas downregulating NLRX1 abolishes MCL1 induced mitophagy. In summary, our data identify PLAA as a novel mediator of mitophagy by regulating MCL1-NLRX1 axis. We propose mitophagy as a target for therapeutic intervention in PLAAND.

The role of RNA methyltransferase METTL3 in gynecologic cancers: Results and mechanisms

N6-methyladenosine (m6A) methylation is the most prevalent mRNA modification in eukaryotes, and it is defined as the methylation of nitrogen atoms on the six adenine (A) bases of RNA in the presence of methyltransferases. Methyltransferase-like 3 (Mettl3), one of the components of m6A methyltransferase, plays a decisive catalytic role in m6A methylation. Recent studies have confirmed that m6A is associated with a wide spectrum of biological processes and it significantly affects disease progression and prognosis of patients with gynecologic tumors, in which the role of Mettl3 cannot be ignored. Mettl3 is involved in numerous pathophysiological functions, such as embryonic development, fat accumulation, and tumor progression. Moreover, Mettl3 may serve as a potential target for treating gynecologic malignancies, thus, it may benefit the patients and prolong survival. However, there is a need to further study the role and mechanism of Mettl3 in gynecologic malignancies. This paper reviews the recent progression on Mettl3 in gynecologic malignancies, hoping to provide a reference for further research.

The landscape of m6A regulators in esophageal cancer: molecular characteristics, immuno-oncology features, and clinical relevance

Background

Squamous cell carcinoma (SCC) and adenocarcinoma (AC) are the two main pathological types of esophageal cancer (EC), which differ in molecular features, genetic variation, and treatment sensitivity. However, as a key process in tumorigenesis and development, the role of N6-methyladenosine (m6A) regulators in esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) is not fully understood.

Methods

This study systematically compared the role of m6A regulators of ESCC and EAC in terms of molecular characteristics, immuno-oncology characteristics, and clinical relevance, and validated our findings in a long-term follow-up patient cohort.

Results

There were many differences in m6A regulators between ESCC and EAC in terms of expression patterns, genetic variation, association with tumor pathways, immune signatures, and immunotherapy sensitivity. Furthermore, VIRMA was identified as a factor with opposite functional and prognostic effects in ESCC and EAC. ESCC patients with high VIRMA expression and EAC patients with low VIRMA expression had a better prognosis. Single-center data showed that low expression of FTO may be associated with superior immunotherapy efficacy in ESCC patients.

Conclusions

The results herein provide novel ideas for understanding the tumor characteristics, occurrence, and development of ESCC and EAC, and suggest new targets for the treatment and intervention of EC.